Prep your ingredients: Clean mushrooms with a damp towel and slice.
Chop the onion and mince the garlic so everything cooks evenly.
Sweat the aromatics: Heat oil in a large pot over medium heat. Add onion with a pinch of salt and cook 5–7 minutes until soft and translucent. Stir in garlic for 30 seconds.
Brown the mushrooms: Add mushrooms and thyme.
Cook 8–10 minutes, stirring occasionally, until they release liquid and edges start to brown. Don’t rush this step—browning builds flavor.
Season and deglaze: Stir in tamari and balsamic. Scrape up any browned bits from the bottom of the pot.
Simmer: Pour in vegetable broth.
Bring to a gentle boil, then reduce to a simmer for 10 minutes to meld flavors.
Add creaminess: Stir in cashew cream or coconut milk and nutritional yeast. Simmer 2–3 minutes more. Taste and adjust salt and pepper.
Blend to desired texture: For a creamy soup with some chunks, blend half the pot using an immersion blender, or transfer 3–4 cups to a blender and return it to the pot.
For ultra-smooth, blend it all.
Finish and serve: Ladle into bowls. Top with chopped parsley or chives and extra cracked pepper. Serve warm with bread.